Long stored FJ1200 not running well

[dozerdude]

After some time in the barn, my FJ of 22 years is not running well.  Over last winter, the carbs leaked the entire contents of the gas tank into the crankcase.  I cleaned the carbs and installed rebuild kits.  When it runs, it acts like it's starving for fuel (backfiring out of the carbs and not taking any throttle).  I'm sure the carbs are clean and adjusted correctly.  Is there any way that the timing could be off due to the vacuum activated ignitor box?  The bike will not run well no matter what I do with the choke or any carb adjustment.  I'm running it on an auxillary gravity-feed gas tank right now.  The diaphrams for the slides are fine, the intake manifolds are not leaking, like I said, the carbs are not dirty and they are adjusted correctly.  Twenty years ago I installed the K&N stage II jet kit and a Supertrapp 4 into 1 header.  It always ran great with this set up until I had to let the bike sit for a few years.  I put in Stabil and stuff, but...  Any ideas you could toss my way would be greatly appreciated.  Thanks for reading.

[FJmonkey]

Start with removing and rebuilding the carbs and cleaning out the tank and lines. Sabil is good for only so long before it turns to gel. The FJ does not like to sit.

[simi_ed]

 You have plugged pilot jets & circuits.  Use plenty of spray carb cleaner & compressed air, or better yet, follow Carb Doc Raforth's directions <http://www.fjowners.com/index.php?topic=655.0>  on how to clean 'em. 

We've all been there & done that.  Trust me, you'll get good at doing the "FJ carb R&R".

[RichBaker]

What brand rebuild kits? Some of the cheap ones are crap....  Also, most cleaned and rebuilt carbs need a second, and somnetimes a third cleaning/going thru.  It isn't easy to get all those little passages cleaned of old, gummed up fuel. BTDT.... a couple times.
It may be cheaper in the long run to get them done professionally, by someone like RPM Randy, or even buy a good NOS set....

[winddancer]

+1 on Randy at RPM